1 seasonal thermal energy storage (stes) for technical experts (architects, engineers, construction...
DESCRIPTION
Contents What is Seasonal Thermal Energy Storage (STES)? Why use STES? History of STES How does it work? Thermal Storage (Types, systems, stratification devices) Serial/Parallel Operation Calculations Where is best used How much does it cost? EINSTEIN Pilot plants & Case Studies 3TRANSCRIPT
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Seasonal Thermal Energy Storage (STES)for technical experts
(architects, engineers, construction industry etc.)
Mr Miguel RamirezDr Shane ColcloughProf Neil J Hewitt
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Contents
What is Seasonal Thermal Energy Storage (STES)? Why use STES? History of STES How does it work? Thermal Storage (Types, systems, stratification devices) Serial/Parallel Operation Calculations Where is best used How much does it cost? EINSTEIN Pilot plants & Case Studies
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Contents
What is Seasonal Thermal Energy Storage (STES)? Why use STES? History of STES How does it work? Thermal Storage (Types, systems, stratification devices) Serial/Parallel Operation Calculations Where is best used How much does it cost? EINSTEIN Pilot plants & Case Studies
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Storing cold during winter for use in summer
Storing heat during summer for use in winter
WHAT IS STES?
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Contents
What is Seasonal Thermal Energy Storage (STES)? Why use STES? History of STES How does it work? Thermal Storage (Types, systems, stratification devices) Serial/Parallel Operation Calculations Where is best used How much does it cost? EINSTEIN Pilot plants & Case Studies
WHY STES? Energy use of buildings accounts for 30-40% of the total
energy consumption in the EU 60-70% of it is consumed for heating by the residential
buildings Heating demand for space heating occurs mostly in
wintertime when solar availability is lower Store solar thermal energy in summer for use in winter
months Northern European countries have average ambient
temperature of approx. 5°C and annual solar irradiation up to 1000 kWh/year m² (Stockholm)
Data source: SoDa-is.com
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Contents
What is Seasonal Thermal Energy Storage (STES)? Why use STES? History of STES How does it work? Thermal Storage (Types, systems, stratification devices) Serial/Parallel Operation Calculations Where is best used How much does it cost? EINSTEIN Pilot plants & Case Studies
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Ancient PersiaIn 400 B.C 60 feet tall brick domes (Yakhchals) with wind catchers were used to store ice and keep cooling in ambient temperatures of 40°C
Romans1st Century A.D. used wells and transported snow to keep their food and wine cold on hot days
Cold HousesIn the 18th-19th century river water or ponds used to maintain low temperatures inside these structures for preserving food (Middleton, England – Glen River, Northern Ireland)
HISTORY OF STES – Storing Cold
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Germany post WWIFirst feasibility studies started in 1920 due to the country limited resources.
USAThe Keck “glass” house in 1933 and MIT house in 1939 both made with glass and high thermal capacity materials for thermal energy storage
Denmark, SwedenDuring the 70’s oil crisis forced governments to look for alternatives. Small and large scale thermal storage systems were built combined with district heating systems
HISTORY OF STES – Storing Heat
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Contents
What is Seasonal Thermal Energy Storage (STES)? Why use STES? History of STES How does it work? Thermal Storage (Types, systems, stratification devices) Serial/Parallel Operation Calculations Where is best used How much does it cost? EINSTEIN Pilot plants & Case Studies
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HOW DOES IT WORK - COMPONENTS
Heat Source Solar Biomass Industrial waste heat..
Thermal Storage High thermal capacity Large volume Low thermal losses
Auxiliary & Distribution system Boiler, Heat pump District Heating network
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ParallelHeat pump, solar collector and STES work independently to meet heat demand
In SeriesSolar collector or STES act as a source for heat pump or in addition to other sources
Serial/ParallelThe heat pump or collector provides heat to the building, dependently or independently
HOW DOES IT WORK - CONFIGURATIONS
Sou
rce:
Sol
ites
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ParallelThe solar collectors are connected directly with the storage tank and charge it with thermal energy during high solar radiation periods. The STES delivers hot water for domestic hot water (DHW) and the space heating system during the heating period (winter).When the temperature of the STES is lower than the required, the heat pump delivers the necessary heat to both the DHW and the space heating system. The heat pump thermal source is external and it can be either air, ground or from waste heat recovery.
HOW DOES IT WORK - CONFIGURATIONS
Solar Collectors
STESHeat Pump (Air/Ground source)
DHW
LOAD
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SeriesThe solar field, STES tank and heat pump are connected in series. Heat is stored during high solar radiation periods. The solar collector can directly act as a source for a heat pump or directly via heat storage. The heat pump must be a water-to-water unit and it can satisfy the hot water demand from both the DHW and the buildings. The storage tank temperature can be maintained within a lower range of temperature according to the operation range of the heat pump’s source. By having a lower STES tank temperature, it reduces the thermal losses from STES.
HOW DOES IT WORK - CONFIGURATIONS
Solar Collectors
STES
Heat Pump
DHW
LOAD
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Series/ParallelThe STES tank is charged by the solar collectors and provides heat to the DHW and buildings. When the temperature within the STES tank is below the minimum required by the load the heat pump starts operating. The heat pump extracts the remaining heat in the store to deliver DHW and space heating to the buildings. In all three cases the heat pump can operate during low electricity cost periods to heat the DHW tank in a cost-effective way. Moreover, an auxiliary system (i.e. gas boiler) must be used to cover the heating demand that cannot be covered by the STES system.
HOW DOES IT WORK - CONFIGURATIONS
Solar Collectors
STESHeat Pump
DHW
LOAD
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Contents
What is Seasonal Thermal Energy Storage (STES)? Why use STES? History of STES How does it work? Thermal Storage (Types, systems, stratification devices) Serial/Parallel Operation Calculations Where is best used How much does it cost? EINSTEIN Pilot plants & Case Studies
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Latent Heat
Chemical Heat
Sensible Heat
THERMAL STORAGE - Types
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Latent Heat
Chemical Heat
Sensible Heat
THERMAL STORAGE - Types
The most common material used to store latent heat are solid-liquid Phase Change Materials (PCM). Thermal energy can absorbed by the PCM in both solid and liquid states. However, they absorb large amounts of heat during the conversion from solid to liquid (melting temperature).PCMs can store 5 to 14 times more heat per unit volume than conventional storage materials such as water, masonry or rock. When thermal energy is absorbed from the PCM storage, it changes from liquid to solid phase releasing its stored latent heat.
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Latent Heat
Chemical Heat
Sensible Heat
THERMAL STORAGE - Types
Chemical or Thermochemical heat storage systems, are promising technology approaches with considerable benefits compared to both the sensible and the latent-heat storage systems. Storage densities can theoretically be up to 10 times above those of the medium water, reducing thus the construction volume.Due to the nature of its process and the low temperature of the stored materials it can almost eliminate thermal losses. The combination of both advantages facilitates the efficient time-based storage of thermal energy and its transport.
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Latent Heat
Chemical Heat
Sensible Heat
THERMAL STORAGE - Types
Sensible heat is the thermal energy transferred to or from a substance which results in a change of temperature. It is the most common and direct way to store heat, however the main draw-backs are the large quantities of material/volumes that needs and the heat losses when the store medium is surrounded by lower temperatures.The use of water tanks for thermal storage is a well known technology. Innovative solutions can minimize heat losses by ensuring optimal water stratification and high efficiency thermal insulation.
Kies/Wasser-W ärm espeicher
Erdsonden-W ärmespeicher
Heißwasser-W ärm espeicher
So m m er W inter
W ä rm ed äm m ungAb dich tu ngSchutzvlies
Kies/Wasser-Wärmespeicher
Erdsonden-W ärmespeicher
Heißwasser-W ärm espeicher
Som m er W in ter
W ärm edäm m ungAbdich tungSchutzvlies
Tank Thermal Energy Storage (TTES) Pit Thermal Energy Storage (PTES)
Borehole Thermal Energy Storage (BTES) Aquifer-Thermal Energy Storage (ATES)
~70 kWh/m³ 1) ~55 kWh/m³ 2)
15-30 kWh/m³ 30-40 kWh/m³1) Jmax=90 °C, Jmin=30 °C without heat pump 2) Jmax=80 °C, Jmin=10 °C gravel-water TES with heat pump
Kies/Wasser-W ärm espeicher
Erdsonden-W ärmespeicher
Heißwasser-W ärm espeicher
Som m er W inter
W ärm edäm mungAbdichtungSchutzvlies
THERMAL STORAGE - Systems
(D 5.5)
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Thermal Energy Storage SystemsTHERMAL STORAGE - Systems
Source: http://solar-district-heating.eu/
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THERMAL STORAGE - Losses
Losses from STES tanks can be high
A: conventional insulation material: λ = 0,05 W/(m·K), insulation thickness s = 0,2 mB: conventional insulation material : λ = 0,05 W/(m·K), insulation thickness s = 2 mC: Vacuum insulation: λ = 0,005 W/(m·K), insulation thickness s = 0,2 m
Time in days
Cooling down curve of a hot water store with a net volume of 10 m3 (cylindric shape: Ø 2 m, height 3,18 m). Start temperature 80 °C, ambient temperature 5 °C
Due to lower surface to volume ratios, large tanks cool down more slowly and are therefore favouredThis has led to a focus on STES in combination with District Heating
Sensible Heat StorageThe types of STES are characterised by different specific usable storage capacities, temperature levels and charging and discharging capacities. Moreover, the usable volumetric storage capacity depends on the used temperature range and the specific volumetric heat capacity of the storage material. These facts must be considered for the technical selection of a certain STES type.
THERMAL STORAGE - Systems
Maximal operational temperatures of the different STES technologies depending on the return flow temperature of the district heating network and usage of heat pumps [source: ITW, USTUTT].
Usable volumetric storage capacity showing dependency of the minimal discharge temperature of the different STES technologies: depending on the return flow temperature of the district heating network and usage of heat pumps [source: ITW, USTUTT].
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THERMAL STORAGE - TTES
TTES
Concrete
Built Onsite
Precast
Steel
MountedOnsite
Factory Mounted
Fiber Vacuum Insulated
Reinforced ConcreteADVANTAGES Additional energy storage capacity
(up to +25%) The material protects the insulation.DISADVANTAGES Heavy structure Requires waterproofing Limitations for pressurized tanks Usually low h/D ratio, poor
stratification
Metallic TankADVANTAGES Lighter structure Easy waterproofing Flexibility in geometry and shapes DISADVANTAGES Very conductive, it can influence
thermal losses Conductivity can destroy stratification
Thermal Storage and stratification
The effective storage of thermal energy in hot water tanks requires both a well isolated tank wall and simple charging and discharging systems, which produce and maintain a thermal stratification reliably in the store. The quality of the thermal stratification within the store has a significant influence on the thermal performance of the solar heating system. Mixing of hot and cold water within the store can reduce the solar yield and can significantly raise the amount of reheating required. Then even the solar heating system can lose the reasonableness.
THERMAL STORAGE - Stratification
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Types of stratification device External: Automatic valves control the flow along the
height of the tank Internal: Hot water inlet height is self-controlled by
water density Reasons to use
Stratification in a STES affects the quality and durability of the stored energy
Diversity of temperature: Solar collectors, heat pumps and conventional boilers operate at different temperatures
Supply and return water temperature affect the stratification within the storage tank
Poorly designed stratification systems affect directly the quality and durability of a TES system
THERMAL STORAGE - Stratification
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Buffer tank Required in thermal plants to
decentralize the energy production from the STES providing independent hot water feeds
It stabilizes the thermal capacity and temperature output of the heat pump
Controls the temperature levels improving thus the heat exchange
THERMAL STORAGE - Buffer
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Contents
What is Seasonal Thermal Energy Storage (STES)? Why use STES? History of STES How does it work? Thermal Storage (Types, systems, stratification devices) Serial/Parallel Operation Calculations Where is best used How much does it cost? EINSTEIN Pilot plants & Case Studies
EXAMPLE OF THE SERIAL/PARALLELSTES OPERATION MODES(EINSTEIN PLANTS CASE)
ChargingThe charging of a STES system starts when thermal energy from the source (solar) is available. Solar thermal energy can be collected during summer months and stored to the STES tank for later usage. It is also possible to store and deliver thermal energy only when the tank has independent circuits for charging and discharging.
SERIAL/PARALLEL OPERATION
Direct Discharging The discharging of a STES system starts with the heating season. The tank delivers heat directly to the buildings through a district heating or direct pipeline. The temperature of the hot water outlet is regulated according to the heating curve of the load. Maximum STES outlet temperatures are typically 80°C, (with pressurized tanks >100°C is possible).
TSTES > 50°C
SERIAL/PARALLEL OPERATION
Heat pump operation The heat pump operates when the STES output temperature is lower than the temperature needed by the load to fully cover the heating demand. Water from STES delivers heat to the evaporation cycle of the heat pump and the condensing cycle provides hot water with sufficient temperature to overcome the load needs.
10°C < TSTES < 50°C
SERIAL/PARALLEL OPERATION
Auxiliary system – BoilerWhen the temperature of the water in the tank drops (10°C) to a level which is out of the efficient operation of the heat pump, the auxiliary system starts. The thermal energy from the STES tank has been completely discharged and the load depends totally on the auxiliary system.
TSTES < 10°C
SERIAL/PARALLEL OPERATION
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Auxiliary system – Boiler/Heat Pump An auxiliary heat source is essential to cover peak load
and for periods when the storage tank is discharged Heat pumps typically are three/four times more efficient
than conventional heaters for the same amount of heat Water-to-water heat pumps have a low return
temperature to the source side. That temperature difference helps the stratification in the storage tank.
Lower temperature at the bottom of the storage tank causes higher collector efficiency and decreases thermal losses through the ground
SERIAL/PARALLEL OPERATION
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Contents
What is Seasonal Thermal Energy Storage (STES)? Why use STES? History of STES How does it work? Thermal Storage (Types, systems, stratification devices) Serial/Parallel Operation Calculations Where is best used How much does it cost? EINSTEIN Pilot plants & Case Studies
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Energy Diagram of a STES system with Heat pump
CALCULATIONS - Diagram
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Q= m.cp.ΔΤ Q: Thermal energy stored m: Mass of substance used for storing heat cp: Specific heating capacity of storing
substance ΔT: Temperature change of storage medium
before and after charging it
CALCULATIONS
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CALCULATIONS Maximum Thermal Energy Stored
The maximum energy stored of a STES system in MWh can be calculated with the equation:
V: Volume (m3)ρ.Cp: Heat capacity of storage medium (MJ/(m3 K)Tmax: Maximum storage temperatureTmin: Minimum temperature
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CALCULATIONS Solar collector outputThe two main factors that determine the efficiency of seasonal thermal energy storage with a heat pump are the solar fraction (SF) and coefficient of performance (COP) of the heat pump. These factors change with changing collector area and storage volume. Solar heating systems are mainly evaluated according to their SF, which is the amount of energy provided by the solar heating system divided by the total energy demand, as shown in Eq.
qc: collector outputQloss: Thermal loss from the systemQhd: Thermal demand
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CALCULATIONS STES system energy balanceThe relation between SF, COP, collector area and storage volume can be calculated considering energy conservation principles, with energy in the storage calculated by the equation:
where qc is the collector output, Whp is the electricity input to the heat pump, Qhd is the heating demand for space heating and DHW if needed, Qloss is the heat loss from the system, and Qtank is the stored energy in the tank. Units in kWh.
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CALCULATIONS Heat Pump performanceThe efficiency of a heat pump in heating mode is determined by the coefficient of performance (COP). The COP of a heat pump indicates the ratio of produced energy to used energy. COP depends on the temperatures of heat source and heat sink, the efficiency of its compressor, and the type of its working medium.
Lowering the temperature difference between the heat source and the heat sink for a heat pump results in a higher COP value. A low temperature heating system and high temperature heat source is therefore beneficial
ηc: Carnot efficiency Tsin, Tsor : Heat sink and heat source temperatures (C)W: work done by compressor, pump and fan (kWh)Qhd: heating demand (kWh)
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CALCULATIONS Size of STES
When the volume of the storage system is known the other dimensions can be calculated. It is assumed that a cylindrical shape tank with RHD=0.6 is used.
RHD: ration height/diameterHacu: height of STES (m)Aacu: Total surface Area of STES (m2)
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Contents
What is Seasonal Thermal Energy Storage (STES)? Why use STES? History of STES How does it work? Thermal Storage (Types, systems, stratification devices) Serial/Parallel Operation Calculations Where is best used How much does it cost? EINSTEIN Pilot plants & Case Studies
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WHERE IS IT BEST USED?
Building type Single House Multi Unit Development New Built (preferred) Existing buildings
Climate Conditions High annual solar
radiation & moderate heat demand in winter is ideal
Heating type District heating Low temperature
Sou
rce:
Ask
o pr
ofes
sion
als
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STES ground conditions Geological structure Land space for Storage Hydrogeological characteristics (aquifers)
Thermal energy source Sufficient area for solar collectors (land, roof) Industrial thermal waste sources (temperature
range, distance to the heat demand point and availability)
District heating grid availability Type of use
Single load – (stable run) Independent dwelling usage (complex controlling
system)
WHERE IS IT BEST USED? - Considerations
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WHERE IS IT BEST USED? – EINSTEIN resources
Location within the EUSpace heating energy demand in the EU vary significantly from country to country. The main factors depend on the building stock, the construction period, building density, prevalent heating systems (eg District Heating) and the local climatic conditions.The best potential for STES system application in Europe are highlighted in the report: “Classification of EU building stock according to energy demand requirements.”
Residential energy demand vs. average ambient temperature. (ACC4: Bulgaria, Romania, Turkey, Croatia; EFTA3: Iceland, Norway and Switzerland; NMS 10: new ten member states since May 2004.
(Source: ECPHEATCOOL).
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WHERE IS IT BEST USED? – EINSTEIN resources
STES integrationGiven the recent energy performance regulations in EU countries it is anticipated that buildings will have lower energy demand (<50kWh/m²yr). In that case it is possible to use lower supply temperatures for space heating systems thereby decreasing thermal losses. That makes STES systems better suited to the integration of low-energy heating systems. Integration of STES with a number of types of heat generation technologies, such as gas boilers, heat pumps, Combined Heat and Power (CHP) and distribution systems are discussed in this document: “Technology assessment HVAC and DHW systems in existing buildings throughout the EU”
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WHERE IS IT BEST USED? – EINSTEIN resources
Design STES systems and EINSTEIN plantsNumerous steps need to be taken to design a STES system. They consist mostly of technical challenges and decisions such as dimension of storage tanks, location, solar field size and heating system retrofitting, need to be studied. Having a transient system which is influenced mostly by weather conditions, makes it possible to predict and determine the behaviour by stationary calculations. A comprehensive guide for planning and designing a STES system can be found here: “Design guidelines for STES systems in Europe”.For an overview of the design and installation of the EINSTEIN demonstration plants please click here.
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WHERE IS IT BEST USED? – Combination of increased energy efficiency and use of renewables
Energy StrategyIn order for STES systems to be most effective, they need to be part of an overall energy strategy. This includes:
reducing the energy demand of the existing building by retrofitting energy efficiency measures
Integrating the use of renewables Integrating specialist solutions including STES
These decisions need to be optimised based on the variables applying for the specific case such as:
Climate Cost Building type
An Evaluation Tool has been developed in EINSTEIN to determinethe most cost effective combination of measures, and a Decision Support Tool to assist with the design of the solar system
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WHERE IS IT BEST USED? – Evaluation Tool
Configuration of the Evaluation tool 1.Definition of study building
• Selection of Climatic area • Selection of type of building• Surface of the building
2. Desired energy reduction • Select Range of savings
3. Calculate the most cost effective solution
•Query to the database of results•- match with the optimal case (s) that meet the savings selected. •- identify the most cost effective combination of passive an active measures(including STES)
4. Results• Best combination option selected• Primary energy savings. (-kWh/year)• Investment required (€)
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EVALUATION TOOL – The most Cost Effective Solution
Software Model for assessing the energy behavior of
existing buildings
Passive retrofitting strategiesSTES
contribution to cost
effectiveness
Evaluation Tool for most cost
effective frame work in
retrofitting
Decision tool for designing and evaluation of
STES
Access the EVALUATION TOOL here
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Decision Support ToolOnce the most cost-effective solution has been determined, a further tool is available as part of the EINSTEIN project to help analyse the best preliminary design of the STES. The DST helps users to identify the most suitable technologies according to specific conditions.
Climatic conditions Space requirements Equipment and integration requirements
(Solar collectors, STES, district heating, heat pumpand auxiliary system)
For further information on the model please click here.
WHERE IS IT BEST USED? – STES Design Tool
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DST DescriptionThe Tool consists of three main parts:
Input data selection Calculations section Results section
Design casesApart from a selection and evaluation tool for STES systems, the tool also allows users to analyse and compare different scenarios. Centralized systems as well as distributed configurations can be studied for each location and each level of heating demand for both existing or new buildings.
For access to the tool please click: DECISION SUPPORT TOOL
WHERE IS IT BEST USED? – STES Design Tool
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WHERE IS IT BEST USED? – Reference single family house
SFH: Single Family house
SFH 84,5 m2
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WHERE IS IT BEST USED? – Reference Multi family house
MFH: Multifamily house (block of flats)
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00
18.00
20.00
22.00
24.00
0.00
50.00
100.00
DHW MFH
h
litre
s of
wat
er
cons
umpt
ion
MFH 676 m2
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WHERE IS IT BEST USED? – Sample outputs
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
0.000 0.050 0.100 0.150 0.200 0.250 0.300
Ratio Total result per period/Primary energy consumed vs Primary energy
% Primary savings
€ sa
ving
/kW
h co
nsum
ed
0% 10% 20% 30% 40% 50% 60% 70% 80% 90%100%0.00
20.0040.0060.0080.00
100.00120.00140.00
Ratio Investment / Primary energy savings vs % Primary energy reduction
best restults (Invest aproach)best results (20 y exploitation aproach)
% Primary savings
Curves of best ratios results (Pareto distribution)
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Contents
What is Seasonal Thermal Energy Storage (STES)? Why use STES? History of STES How does it work? Thermal Storage (Types, systems, stratification devices) Serial/Parallel Operation Calculations Where is best used How much does it cost? EINSTEIN Pilot plants & Case Studies
HOW MUCH DOES IT COST?
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The costs and financial benefits of seasonal thermal energy storage vary widely.
Variables include: Climate (solar irradiation, outdoor temperature) Heating demand Type of STES District Heating integration Financial variables including inflation rate, fuel
inflation rate, internal rate of return, etc.
HOW MUCH DOES IT COST? – The STES tank
The diagram above shows the costs of a wide range of STES tank sizes used for large district heating systems. The cost of the investment decreases with size.
The cost of the EINSTEIN STES tanks for both demonstration tanks are highlighted.
The 23m3 Multiunit tank in Lysekil is on a different scale and costs €700/m3 60
Passive House with solar DHW and space heating with STES
Quickest payback was for solar DHW and space heating system excl. STES (lowest cost option in year 16 & again in year 24 after refurbishment).
When the STES was added to the solar DHW & Space Heating system it represented the lowest cost option in year 33.
Note that the STES is required as an integral element of the system in order to avoid technical problems with stagnation.
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Source: Colclough & Griffiths, Applied Energy Journal 2016
HOW MUCH DOES IT COST? – Overall cost of heating
Example of a single dwelling STES installation
Costs presented include systems, operating costs and fuel and are adjusted for inflation and company discount factor (Net Present Value).
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Description Multiunit development
Number of units 10 (4 commercial, 6 residential)
Total floor area {m2} 381 plus 390 = 781 Total
Solar Array {m2} 50
Diurnal Store {m3} 3.3
STES Size {m3} 23Space heating energy demand {kWh}
53,422
DHW energy demand {kWh} 7,417Total NPV cost over 40 years {€} 405,415Payback peiod {Years} 17Saving compared with non Solar STES 27%
Building renovated to Passive House standard
Solar heating system with STES used
Payback achieved after 17 years
HOW MUCH DOES IT COST?
Example of a Small scale STES installation10 unit development with solar DHW and space heating with STES in Lysekil, Sweden
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The total cost of providing DHW and space heating is shown opposite. Costs include systems, operating costs and fuel and are adjusted for inflation and company discount factor (Net Present Value).
The costs of heating with District Heating (€514,492) exceeds that of using solar heating with STES with DH as backup (€405,415) over the 40 years considered
HOW MUCH DOES IT COST?
Example of a Small scale STES installation10 unit development with solar DHW and space heating with STES in Lysekil, Sweden
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Contents
What is Seasonal Thermal Energy Storage (STES)? Why use STES? History of STES How does it work? Thermal Storage (Types, systems, stratification devices) Serial/Parallel Operation Calculations Where is best used How much does it cost? EINSTEIN Pilot plants & Case Studies
EINSTEIN pilot plants
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EINSTEIN PILOT PLANT - Bilbao
Spanish Demonstration plantSpanish Demo plantSolar collectors
Flat plate
Surface Area 62m2
Tilt Angle 40°Orientation SouthWorking fluid GlycolBuffer Tank Vol.
2m3
STES Tank Vol.
180m3
BuildingUsable Area 1050m2
Annual Heat Demand
83MWh/yr
Heating Range T Low Temp.
Further details are available from the following reports:• Design and installation• Monitoring• Impact Assessment• Overall report
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EINSTEIN PILOT PLANT - Bilbao
Hydraulic scheme
STES storage
Building
Solar generation
Heat Pump Buffer
Boiler
6811 days time of assembly
EINSTEIN PILOT PLANT - Bilbao
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EINSTEIN PILOT PLANT - Bilbao
STES Innovative design Double independent tank. Modular construction. Inner tank: 6 m ; Height 6.45 m wet
(6.70 total) Outer tank: 7.10 m; Height 8.05 m less thermal bridges due to absence of supports
Innovative insulation. Bottom insulation over the ground: 0.45 m Expanded clay granulates. Regular distribution of charges over the ground
(not increased in perimeter)
Lateral and upperside: new PUR recycled granules. Lateral side 0.55 m; upper side 0.87m Blowable type insulating material.
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EINSTEIN PILOT PLANT - Bilbao
Pumps, pipelines, HX, buffer tank
Heat exchanger primary/secondary circuits
Secondary circuit, hydraulic collectors
Buffer tank, 2 m3
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EINSTEIN PILOT PLANT - Bilbao
Charging of STES tank
Max Temp 66.7°C
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EINSTEIN PILOT PLANT - Zabki
Polish Demonstration PlantStorage SystemType TTESVolume 800 m3
Tilt Angle 40°Orientation SouthWorking fluid Glycol
District Heating systemTotal Length 150m2
Pipes 2x De65 flexible, preinsulated polibutylene pipes in PEHD casing
BuildingUsable Area 794 m2
Peak Heat Demand
75kW
Heating Range High Temp.
Further details are available from the following reports:• Design and installation• Monitoring• Impact Assessment• Overall report
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EINSTEIN PILOT PLANT - Zabki
8 mø14 m
10 cm PUR+
36-40 cm XPS
70 cm mineral wool
38 cm glass foam
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EINSTEIN PILOT PLANT - Zabki
Buffer Tank
Gas Boiler
HEAT PUMP
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EINSTEIN PILOT PLANT – Zabki SCADA system
Brennwert-KesselGas
H eizzentra leF lachkollektoren
W ärm enetz
So larne tzSaisonalerW ärm espeicher
W ärm eüber-gabestation
Central Heating
Plant
Solar Collectors
Seasonal Thermal Energy Store
Solar Network
Heat Distribution
Network
Heat Transfer Substation
CASE STUDIES
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STES Tanks under House 1st European 100% Solar House Oberburg, Switzerland In operation since January 1990
CASE STUDIES
Sou
rce:
Jen
ni E
nerg
iete
chni
k
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Oberburger Sonnenhaus First multi-family dwelling to be heated completely
with solar energy Oberburg, Switzerland 276m² of solar collectors 205m³ thermal storage tank
CASE STUDIES
Sou
rce:
Jen
ni E
nerg
iete
chni
k
3.000 m² Flat plate coll. 4500 m³ Water tank
Hamburg (1996)
Friedrichshafen (1996)
Neckarsulm (1997) Steinfurt (1998)
Rostock (2000) Hannover (2000)
5.900 m² Flat plate coll. 63.300 m³ BTES
1.000 m² Solar-roof 20.000 m³ ATES
4.050 m² Flat plate coll. 12.000 m³ Water tank
510 m² Flat plate coll. 1.500 m³ Pit TES
(Gravel/Water)
1.350 m² Flat plate coll. 2.750 m³ Water Tank
Source: USTUTTCASE STUDIES
Chemnitz, 1. phase (2000)
Munich (2007)
Eggenstein (2008)
Attenkirchen (2002)
Crailsheim (2007)
540 m² Vacuum
tubes 8.000 m³ Pit TES
(Gravel/Water)
2.900 m² Flat plate coll. 5.700 m³ Water tank
1.600 m² Flat plate coll. 4.500 m³ Pit TES
(Gravel/Water)
800 m² Solar-Roof 9.850 m³ Water tank &
Boreholes
7.500 m² Flat plate coll. 37.500 m³ BTES
Source: USTUTTCASE STUDIES
81
Seasonal Thermal Energy Storage (STES)for technical experts
(architects, engineers, construction industry etc.)
Mr Miguel RamirezDr Shane ColcloughProf Neil J Hewitt